Effects of dietary lipid and carbohydrate levels and chronic 3,5,3′-triiodo-L-thyronine treatment on growth, appetite, food and protein utilization and body composition of immature rainbow trout, Oncorhynchus mykiss, at low temperature

Effect of dietary levels of lipid and carbohydrate on growth performance, body composition, nitrogen excretion and plasma glucose levels in rainbow trout reared at 8 or 18°C

“…These 2 effects of water temperature are opposed: the first might decrease whereas the second might increase the digestibility of food at high temperature. This opposition might explain why an effect of water temperature on digestibility was not clearly proven in trout (Cho, 1987;Watanabe et al, 1989;M6dale et al, 1991 (Brauge et al, 1994 Higgs et al (1992) (Adron et al, 1976;Reinitz et Hitzel, 1980;Watanabe, 1982 The ammonia excretion of trout had a typical course after feeding (Rychly and Marina, 1977;Kaushik, 1981 The pattern of nitrogen excretion depends on the species, the size and composition of the meal, and on the water temperature (Kaushik, 1980(Kaushik, , 1981Kaushik and OlivaTeles, 1985;Cui and Liu, 1990). The effect of water temperature on feed intake (Kaushik, 1981) (Bergot, 1979;Himick et al, 1991) and in 300 g trout held in seawater at 9°C (Brauge et al, 1994) (Garin, 1984).…”

“…This effect was more pronounced at low temperature. Growth of trout held at 6.5°C was also shown to be depressed when dietary glucose level reaches 15% of the diet (Higgs et al, 1992). (Kim and Kaushik, 1992).…”

Effects of dietary thyroid hormones on the red drum (Sciaenops ocellatus)

“…This conclusion is supported by the observation that total body ash was consistently increased by T 3 treatment. Selective effects of thyroid hormone on weight and length also have been observed in salmonids (Higgs et al 1982(Higgs et al , 1992, indicating a potentially greater sensitivity of nonskeletal tissue to thyroid hormone supplementation. Gross morphological abnormalities were not observed in red drum fed highest doses of thyroid hormone, although the low CF of these fish resulted in an emaciated appearance.…”

“…Our control diet was therefore capable of stimulating a maximal production of endogenous thyroid hormones, and the deleterious effects of exogenous T 3 we observed were thus most likely due to the induction of hyperthyroidism. As the efficacy of thyroid hormone administration has been shown to be dependent on diet composition (Fagerlund et al 1984;Higgs et al 1992), it is possible that thyroid hormones would be a more effective anabolic agent when administered to red drum made hypothyroid by reduced ration, diet quality, or stress.…”

Influence of Iodine on Efficiency of Fish

“…For this purpose in practice of domestic and foreign fish breeding various stimulators are already used at growing of thresh fish, including some hormonal preparations. For example, some researchers (Garg, 2007;Higgs, 1992) suggest to use the diets enriched by low doses of L-thyroxin (up to 50 mg/kg) as a result of such feeding besides high fish growth rates, low coefficient of conversion of forage, high rates of comprehensibility of protein and enzymes activity of digestive tract are noted. According to the authors, there is no risk for consumers of the given fish in connection with high level of hormone metabolism and its removal from the organism.…”